Various devices for angular connection of a tube end and a sheet metal element are known in which an opening has been drilled with dimensions at least equal to those of the outside section. Thus, for connecting tubes in the openings of tube plates of heat exchangers, expansion and welding are currently used. Force-fitting connection of tubes in openings as a result of the insertion of a ring solid with the opening, as described in the patent FR. No. 2 477 920, is also known.